<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8" />
		<title>姓名案例_watch实现</title>
		<script type="text/javascript" src="../js/vue.js"></script>
	</head>
	<body>
		<!-- 准备好一个容器-->
		<div id="root">
			姓：<input type="text" v-model="firstName"> <br/>
			名：<input type="text" v-model="lastName"> <br/>
			全名：<span>{{fullName}}</span>
		</div>

		<script type="text/javascript" >
			new Vue({
				el:'#root',
				data:{
					firstName:'张',
					lastName:'三',
					fullName:''
				},
				watch:{
					firstName:(value)=>{
						setTimeout(()=>{
							// console.log(this)
							this.fullName = value + '-' + this.lastName
							// console.log('姓被别人改了')
						},1000)
					},
					lastName:{
						immediate:true,
						handler(value){
							this.fullName = this.firstName + '-' + value
						}
					}
				}
			})

		</script>
	</body>
</html>